For the pastry, place the flour and salt in a large mixing bowl. Add the water and lemon juice. Mix to combine and then tip out onto a floured work surface. Briefly knead to form a rough, but evenly combined, dough.
Place the pastry in the fridge to rest for 1-2 hours.
On a lightly floured work surface, roll the pastry out into a rectangle approximately 50x30cm/20x12in. Slice the butter and lay this over two-thirds of the dough. Fold the unbuttered dough third over the buttered one, then flip that over the remaining buttered third so that the butter is wrapped inside the dough. Take a rolling pin and lightly roll the upper surface of the dough to press out any air bubbles. Seal the edges with a sharp whack of the rolling pin.
Give the pastry what is known as one single turn – fold the bottom third of the pastry up, then the top third down. Roll the pastry out towards the folded edges until it measures roughly 60x25cm/23x10in, then fold the pastry in by thirds again.
Give the pastry a further two turns, without resting in between. Place the pastry on a plate, cover with cling film and transfer to the fridge to chill for 30 minutes.
Preheat the oven to 200C/400F/Gas 6 and line a baking tray with baking paper.
For the filling, in a bowl combine the dried herbs, salt and pepper, pork mince, Worcestershire sauce, sage and thyme. Stir, then add breadcrumbs. Mix well.
Remove the pastry from the fridge and roll it into a fairly shallow rectangle at least 24cm/9½in long. If necessary, trim the edges to make a neat rectangle.
Roll the meat into a long, thin sausage, approximately the same length as the pastry. (Don’t make it too thick or the sausage will not cook.)
Place the sausage on the pastry and roll the pastry around the sausage. Brush some egg wash on to seal the edge of the pastry. Trim any the excess pastry and discard.
Cut the sausage roll into three equal parts, then divide each part into three or four mini sausage rolls. Brush with egg wash all over the top.
Place the rolls on the lined baking tray and bake for 20 minutes, or until puffed and golden-brown.